Haier HPU-42CV03 Service Manual page 43

2. Automatic run
1). Cooling-heating type
After the machine being started and running mode changes to AUTO, the system will
decide running mode according to difference between the present room temperature and
setting temperature, then runs as the decided mode. In the following selections, Tr means
room temperature and Ts means setting temperature.
Select running mode according to the following conditions at the first time to enter
Auto mode:
Tr≥Ts-3℃ to select cooling mode (with setting temperature being Ts +3)
Tr＜Ts-3℃ to select heating mode (with setting temperature being Ts)
After the system entering auto run mode, the running mode can convert automatically
according to variation of room temperature between cooling and heating. If the unit is in
cooling mode, when the temperature arrives stop value, the compressor stops; the system
will measure the temperature after compressor stops for 3 minutes. At this time, if Tr＜
Ts-3℃, the unit will enter heating mode, or it will still be cooling mode. If the unit is in
heating mode, when the temperature arrives stop value, the compressor stops; the
system will measure the temperature after compressor stops for 3 minutes. At this time, if
Tr＜Ts+3℃, the unit will enter cooling mode, or it will still be heating mode.
If the unit is in heating mode, when indoor heat exchanger temperature is over 63℃,
the unit will turn into cooling mode automatically, in 1 hour, the indoor heat exchanger
temperature will not be limited, and heating operation will stop temporarily, 1 hour later,
the system will adjust the working mode due to the above conditions.
If the unit is in heating mode for the first time, compressor motor will start up, within 8
minutes the
system will not measure indoor ambient temperature, the remote controller will be off.
Ts-3℃
2). Single Cooling type
Select running mode according to the following conditions at the first time to enter
Auto mode:
Tr≥Ts+3℃
Tr＜Ts-3℃
After entering Auto mode, the operation mode can be changed between cooling
mode and fan mode according to indoor ambient temperature: if the unit now is in cooling
mode, when Tr＜Ts-3, the mode will be changed to Fan; if the unit is in Fan mode, when
Commercial Air Conditioner
low
low
ventilation
high high
to select cooling mode
to select blowing mode
42
Model: HPU-42CV03
Ts+3℃
Ts-3℃
HPU-42HV03